The political groups of the European Parliament are the officially recognised parliamentary groups consisting of legislators of aligned ideologies in the European Parliament. Majorities in the Parliament depend on how each group vote and what deals are negotiated among them. The European Parliament is unique among supranational assemblies in that its members (MEPs) organise themselves into ideological groups, rather than national cleavages.

Each political group is assumed to have a set of core principles, and political groups that cannot demonstrate this may be disbanded. A political group of the European Parliament usually constitutes the formal parliamentary representation of one or two of the European political parties (Europarty), sometimes supplemented by members from other national political parties or independent politicians. In contrast to the European political parties, it is strictly forbidden for political groups to organise or finance the political campaign during the European elections since this is the exclusive responsibility of the parties.

There are other incentives for MEPs to organise in parliamentary groups: besides the political advantages of working together with like-minded colleagues, groups have some procedural privileges within Parliament (such as group spokespersons speaking first in debates, group leaders representing the group in the Parliament's Conference of Presidents), and groups receive a staff allocation and financial subsidies.

Status Although most of the political groups in the European Parliament correlate to a corresponding political party, there are cases where members from two political parties come together in a shared political group. For example, the European Free Alliance (half a dozen MEPs in the ninth Parliament) and the European Green Party (over 50 MEPs in the ninth Parliament) have, since 1999, felt they are stronger by working together in the European Greens–European Free Alliance group than they would have as stand-alone groups (especially for the EFA, which would not otherwise have enough members to constitute a group). The same is true of the Renew Europe group, most of whose members are from the Alliance of Liberals and Democrats for Europe Party, but also includes a dozen from the small European Democratic Party. Both have also had independents and MEPs from minor parties also join their group. For a group to be formally recognised in Parliament, it must fulfil the conditions laid down in the relevant European Parliament Rule of Procedure.

This lays down the minimum criteria a group must meet to qualify as a group. The numerical criteria are 23 MEPs (at 3.3 percent, a lower threshold than in most national parliaments), but they must come from at least one-quarter of Member States (so currently at least seven). They must also share a political affinity and submit a political declaration, setting out the purpose of the group, the values that it stands for and the main political objectives which its members intend to pursue together. While 23 MEPs from one-quarter of Member States would also be sufficient to register a European political party, forming a European party is not a requirement to form a group, as long as the criteria of political affinity is met. The requirement of political affinity was put to the test in July 1999, when a varied group of non-attached members, ranging from the liberal Bonino List in Italy to the French National Front, tried to create a new technical group, but Parliament decided that the new group did not, by its own admission, meet the requirement for political affinity. This decision was challenged at the CJEU, which found in Parliament's favour. Further questions were asked when MEPs attempted to create a far-right group called Identity, Tradition, Sovereignty (ITS). This generated controversy and there were concerns about public funds going towards a far-right group.

Attempts to block the formation of ITS were unsuccessful, but ITS were blocked from leading positions on committees, when members from other groups declined to vote for their candidates, despite a previous tradition of sharing such posts among members from all groups. These events spurred MEPs, mainly from the largest two groups, to approve a rise in the threshold for groups to its current levels, having previously been even lower. This was opposed by many MEPs, notably from smaller Groups but also from the Liberal Group, arguing that it would be detrimental to democracy, whilst supporters argued that the change made it harder for a small number of members, possibly on the extremes (including the far right), to claim public funds.

Internal structure Groups are often based around a single European political party (e.g. the European People's Party or the Party of European Socialists), joined by other national parties and independent MEPs. Other groups include more than one European party, such as the Greens–European Free Alliance group. While there is no group not centred on at least one European party, the presence of a European party is not a requirement. Each group appoints a leader, referred to as a "president", "coordinator", or "chair". The chairs of each group meet in the Conference of Presidents to decide what issues would be dealt with at the plenary session of the European Parliament. Groups can table motions for resolutions and table amendments to reports.

Spectrum Composition of the 10th European Parliament

Positions +Ideological spectrum of the European ParliamentGroupIdeologyLeft–right spectrumEuropean integrationThe Left in the European Parliament (The Left)Democratic socialismLeft-wingSoft EuroscepticGreens–European Free Alliance (Greens/EFA)Green politicsCentre-left to left-wingPro-EuropeanProgressive Alliance of Socialists and Democrats (S&D)Social democracyCentre-leftPro-EuropeanRenew Europe (Renew)LiberalismCentre to centre-rightPro-EuropeanEuropean People's Party Group (EPP)Christian democracy, conservatismCentre-rightPro-EuropeanEuropean Conservatives and Reformists Group (ECR)National conservatism, Atlanticism, right-wing populismRight-wing to far-rightSoft EuroscepticPatriots for Europe (PfE)National conservatism, right-wing populismRight-wing to far-rightEuroscepticEurope of Sovereign Nations Group (ESN)Ultranationalism, ultraconservatism, right-wing populism, neo-fascismFar-rightHard Eurosceptic

Analyses National media focus on the MEPs and national parties of their own member state, neglecting the group's activities and poorly understanding their structure or even existence. Transnational media coverage of the groups per se is limited to those organs such as the Parliament itself, or those news media (e.g. EUObserver or theParliament.com) that specialise in the Parliament. These organs cover the groups in detail but with little overarching analysis. So although such organs make it easy to find out how a group acted on a specific vote, they provide little information on the voting patterns of a specific group. As a result, the only bodies providing analysis of the voting patterns and Weltanschauung of the groups are academics. Academics analysing the European political groups include Simon Hix (London School of Economics and Political Science), Amie Kreppel University of Florida, Abdul Noury (Free University of Brussels), Gérard Roland, (University of California, Berkeley), Gail McElroy (Trinity College Dublin, Department of Political Science), Kenneth Benoit (Trinity College Dublin – Institute for International Integration Studies, IIIS), Friedrich Heinemann, Philipp Mohl, and Steffen Osterloh (University of Mannheim – Centre for European Economic Research).

Groups cohesion

Cohesion is the term used to define whether a group is united or divided amongst itself. Figure 1 of a 2002 paper from European Integration online Papers (EIoP) by Thorsten Faas analysed the groups as they stood in 2002. The results for each group are given in the adjacent diagram with the horizontal scale scaled so that 0% = totally split, 100% = totally united."Why Do MEPs Defect? An Analysis of Party Group Cohesion in the 5th European Parliament" by Thorsten Faas, 12 March 2002 original figure estimated from "Figure 1: Cohesion in the EP by Party Groups"

+Group cohesion (2002)GroupCohesionSource PESapprox 90% ELDRapprox 90% G/EFAapprox 90% EPP-EDapprox 80% UENapprox 70% EUL/NGLapprox 65% TGIapprox 50% NIapprox 45% EDDapprox 35%

G/EFA, PES, and ELDR were the most united groups, with EDD the most disunited.

Proportion of female MEPs

The March 2006 edition of Social Europe: the Journal of the European Left included a chapter called "Women and Social Democratic Politics" by Wendy Stokes. That chapter gave the proportion of female MEPs in each Group in the European Parliament. The results for each Group are given in the adjacent diagram. The horizontal scale denotes gender balance (0% = totally male, 100% = totally female, but no Group has a female majority, so the scale stops at 50%)."Social Europe: the journal of the European Left", issue 4, March 2006 original figure taken from chapter "Women and Social Democratic Politics" by Wendy Stokes, Senior Lecturer in Politics, London Metropolitan University

+Group percentage female (2006)GroupPercentage femaleSource G/EFA47.6% ALDE41% PES38% EUL/NGL29% EPP-ED23% UEN16.8% IND/DEM9%

G/EFA, PES, and ALDE were the most balanced groups in terms of gender, with IND/DEM being the most unbalanced.

Party relations The European Parliament does not form a government in the traditional sense and its politics have developed over consensual rather than adversarial lines as a form of consociationalism. No single group has ever held a majority in Parliament. Historically, the two largest parliamentary formations have been the EPP Group and the PES Group, which are affiliated to their respective European political parties, the European People's Party (EPP) and the Party of European Socialists (PES). These two groups have dominated the Parliament for much of its life, continuously holding between 50 and 70 percent of the seats together. The PES were the largest single party grouping up to 1999, when they were overtaken by the centre-right EPP.

In 1987, the Single European Act came into force and under the new cooperation procedure the European Parliament needed to obtain large majorities to make the most impact. So the EPP and PES came to an agreement to cooperate in the Parliament. This agreement became known as the grand coalition. Aside from a break in the fifth Parliament, it has dominated the Parliament for much of its life, regardless of necessity. The grand coalition is visible in the agreement between the two groups to divide the five-year term of the President of the European Parliament equally between them, with an EPP president for half the term and a PES president for the other half, regardless of the actual election result.

Group cooperation Table 3 of 21 August 2008 version of working paper by Hix and Noury gave figures for the level of cooperation between each group (how many times they vote with a group, and how many times they vote against) for the Fifth and Sixth Parliaments, where 0% = never votes with, 100% = always votes with. "After Enlargement: Voting Patterns in the Sixth European Parliament", by Simon Hix and Abdul Noury, LSE/ULB, 21 August 2008 original figure taken from "Table 3. Party Competition and Coalition Patterns"

+Group cooperation (Sixth Parliament)GroupNumber of times voted with (%)SourcesEUL/NGLG/EFAPESALDEEPP-EDUENIND/DEMNI EUL/NGLn/a75.462.048.039.642.245.548.6 G/EFA75.4n/a70.359.247.445.140.343.0 PES62.070.3n/a75.368.462.842.952.3 ALDE48.059.275.3n/a78.072.448.053.7 EPP-ED39.647.468.478.0n/a84.354.064.1 UEN42.245.162.872.484.3n/a56.864.7 IND/DEM45.540.342.948.054.056.8n/a68.1 NI48.643.052.353.764.164.768.1n/a